Stripper Containing an Acetal or Ketal for Removing Post-Etched Photo-Resist, Etch Polymer and Residue

Abstract

The current invention describes a formulation comprising of acetal or ketal as a solvent, a polyhydric alcohol, water and pH adjuster. These formulations should have a pH at least 7 or higher. Formulations in this invention can optionally contain water-soluble organic solvents as co-solvent, corrosion inhibitors and fluorides. The formulations in this invention can be used to remove post-etched organic and inorganic residue as well as polymeric residues from semiconductor substrates.

1 . A formulation to remove post-etched organic and inorganic residue and photoresist from semiconductor substrates, comprising: 
 an acetal or a ketal solvent;    water;    a polyhydric alcohol; and    a pH adjuster to adjust the formulation having a pH at least 7 or higher.    
     
     
         2 . The formulation of  claim 1  wherein the acetal or the ketal solvent having a formula selected from the group consisting of formula I, formula II and combinations thereof:  
       
         
           
           
               
               
           
         
         wherein n≧1 and R 1 , R 2 , R 3 , R 4  and R 5  are each independently H, alkyl, or phenyl.  
       
     
     
         3 . The formulation of  claim 1  wherein the acetal or the ketal solvent is selected from the group consisting of tetramethoxypropane, tetramethoxyethane, malonaldehyde bis(methyl acetal), phenylacetaldehyde dimethyl acetal, benzyladehyde dimethyl acetal, phenylacetaldehyde ethylene acetal, chloroacetaldehyde dimethyl acetal, Chloroacetaldehyde diethyl acetal, 1,3-dioxolane, trioxane, and mixtures thereof  
     
     
         4 . The formulation of  claim 1  wherein the polyhydric alcohol is selected from the group consisting of ethylene glycol, propylene glycol, glycerol, butanediol, pentanediol and mixtures thereof.  
     
     
         5 . The formulation of  claim 1  wherein the pH adjuster is selected from the group consisting of Tetrabutylammonium hydroxide (TBAH), Tetramethylammonium hydroxide (TMAH), Tetramethoxypropane (aka malonaldehyde bis(methyl acetal) (TMP), Potassium hydroxide (KOH), Benzyltrimethylammonium hydroxide (BzTMAH), and mixtures thereof.  
     
     
         6 . The formulation of  claim 1  wherein the range of the acetal or the ketal solvent is about 0.01% to 90% by weight; the range of the polyhydric alcohol is about 1% to 80% by weight, the range of water is about 1% to 80% by weight and the range of the pH adjuster is about 0.1% to 50% by weight.  
     
     
         7 . The formulation of  claim 1  further comprising a fluoride.  
     
     
         8 . The formulation of  claim 7  wherein the fluoride is selected from the group consisting of Tetrabutylammonium fluoride, Tetrapropylammonium hydroxide, Tetraethylammonium hydroxide, Tetramethylammonium fluoride, Ammonium hydroxide, and mixtures thereof.  
     
     
         9 . The formulation of  claim 1  further comprising a corrosion inhibitor.  
     
     
         10 . The formulation of  claim 9  wherein the corrosion inhibitor is selected from the group consisting of tolyltriazole, benzotriazole, catechol, gallic acid and mixtures thereof.  
     
     
         11 . The formulation of  claim 1  further comprising an organic solvent.  
     
     
         12 . The formulation of  claim 11  wherein the organic solvent is selected from the group consisting of Tetrahydrofurfuryl alcohol, Propylene ether, and mixtures thereof.  
     
     
         13 . The formulation of  claim 1  further comprising a fluoride, a corrosion inhibitor and an organic solvent.  
     
     
         14 . A formulation to remove post-etched organic and inorganic residue and photoresist from semiconductor substrates, comprising: 
 from 20 to 55% by weight of Glycol ether;    from 10 to 55% by weight of Tetramethoxypropane;    from 1 to 15% by weight of Tetramethylammonium hydroxide;    from 0.5 to 5% by weight of Tolyltriazole;    from 5 to 25% by weight of Propylene glycol, and    from 40 to 60% by weight of Water;    wherein the formulation has a pH of 7 or higher.    
     
     
         15 . A method for removing post-etched organic and inorganic residue and photoresist from semiconductor substrates, comprising; contacting the substrate with a formulation comprising an acetal or ketal solvent, a base, water and a polyhydric alcohol, such formulations having a pH at least 7 or higher.  
     
     
         16 . The method of  claim 14  wherein the formulation further comprising a fluoride.  
     
     
         17 . The method of  claim 14  wherein the formulation further comprising a corrosion inhibitor.  
     
     
         18 . The method of  claim 14  wherein the formulation further comprising an organic solvent.  
     
     
         19 . The method of  claim 14  wherein the formulation further comprising a fluoride, a corrosion inhibitor and an organic solvent.